Nooksack River basin rule amendment

In May 2020, we amended the existing instream flow rule for the Nooksack River basin, or Water Resource Inventory Area (WRIA) 1, in order to meet the requirements of the Streamflow Restoration law. The rule amendments:

  • Establish domestic permit-exempt groundwater withdrawal limits for new users.
  • Add flexibility for projects that retime high flows for instream resource benefits.
  • Make minor technical corrections to clarify existing language and conform it to the updated language.

The rule amendment takes effect on June 27, 2020. The amended rule language, supporting documentation, and other information is available on our WRIA 1 rulemaking webpage.

This action is part of the 2018 Streamflow Restoration law, which requires fifteen watersheds to develop locally-approved watershed plans. Despite great effort, the local WRIA 1 planning group was not able to meet their Feb. 1, 2019 deadline. As a result, Ecology was obligated by the law to adopt a rule by Aug. 1, 2020.

For more information on the law, visit our Streamflow restoration webpage. 

Domestic Withdrawal Limits

The updated rule sets withdrawal limits for new homes in WRIA 1 using new permit-exempt wells for indoor and outdoor domestic water use. The withdrawal limits apply to building permit applicants who:

  • Receive a building permit for a new home in the Nooksack River basin on or after June 27, 2020, AND
  • Use a permit-exempt well drilled on or after June 27, 2020 for their domestic supply for the new home.

The new withdrawal limits do not apply to:

  • Users outside of the Nooksack River basin (WRIA 1).
  • Existing homeowners.
  • Those with a building permit approved before June 27, 2020.
  • Those using a well drilled before June 27, 2020. 



The updated rule continues the $500 fee established in the 2018 law for new building permits associated with new household permit-exempt wells.

Adding flexibility

The amended rule provides flexibility for projects that retime seasonal high flows, improving streamflow during crucial periods to benefit instream resources.


Minor technical updates

The amendment made minor updates to clarify existing language and conformed it to the updated language.

Supporting documents and analysis

As part of the required rulemaking process we published a Final Rule Supporting Document that includes:

  • The consumptive use estimated for new domestic permit-exempt wells in the WRIA for the 20 year planning horizon (2018-2038)
  • Projects and actions to offset potential impacts to instream flows associated with the new domestic permit-exempt domestic water use (2018-2038)
  • Adaptive management planning provision
  • An evaluation for Net Ecological Benefit (NEB)

Additionally, as part of the rule making process we published:

  • Concise explanatory statement (responding to comments)
  • Implementation plan
  • SEPA documentation
  • Final regulatory analysis (economic analysis).

For more information on the law, visit our Streamflow Restoration webpage.

Projects & actions

As required under the Streamflow Restoration law, we identified projects and actions that offset the domestic water use of new homes and achieved net ecological benefit (NEB) in the Nooksack River basin. As of May 2020, eight of the projects were funded or partially funded, and several more are seeking funding through our Streamflow Restoration competitive grant program

Adaptive management

To address uncertainties, we developed an adaptive management approach; information on this is available in the Final Rule Supporting Document. Adaptive management is an iterative and systematic decision-making process and framework that aims to reduce uncertainty over time and help meet performance goals by learning from the progress and outcomes of projects and actions.